Hot-air furnace.



F. E.. NELSON.

HOT AIR PURNAUE.

APPLIOATIONHLED APR. 13, 1908.

Patented June 15,1909.

2 SHEETS-SHEET l.

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F. E. NELSON.

HOT AIR PURNAGE.

` APPLICATION FILED APB. 1a, 1908.

' 2 SHEETS-SHEET 2.

Patented June 15, 1909.

FRANK E. NELSON, OF LOS ANGELES, CALIFORNIA.

HOT-.AIR FURNACE.

Specification of Letters Patent.

Application led April 13, 1908.

Patented June 15, 1909.

Serial No. l226,711.

To all whom it may concern.'

Be it known that I, F RANK E. NELSON, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and State ofCalifornia, have invented new and useful Improvements in Hot-AirFurnaces, of which the following is a specication.

My invention relates to hot air furnaces, and one of its objects is theprovision of a furnace constructed with a view to burning refuse softcoal and hydrocarbon, and this in such manner that no danger ofexplosion is incurred and leakage of hydrocarbon from the furnace isprecluded.

Another object of the invention is the provision of a hot air furnaceembodying such a construction that the products of combustion radiatepractically all of their heat before the same'are discharged from thefurnace and the said heat is used to the best advantage in raising thetemperature of fresh air conducted through the furnace to the apartmentsto be heated.

Another object is the provision of a hot air furnace embodying a simpleand practical construction whereby the number of radiating flues and thecapacity of the furnace as a whole may be conveniently increased asoccasion demands.

Other objects and advantages of the invention will be fully understoodfrom the following description and claim when the same are read inconnection withV the drawings, accompanying and forming part of thisspecification, in which:

Figure l is a front elevation of a furnace constituting a practicalembodiment of my invention. Fig. 2 is a vertical cross-section of thesame. Fig. 3 is a verticalsection taken through the longitudinal centerof the furnace. Fig. 4c is a perspective View of the furnace dome. Fig.5 is a perspective view of one of the unions employed in eectingconnection between the radiating ilues of the furnace and between theuppermost of said flues and the uptake orV smoke pipe. Fig. 6 is anenlarged, detail section of a portion of one of said connections.

Similar letters designate corresponding parts in all of the views of thedrawings, re-

erring to which:

A is the casing of my novel furnace, which is built quite thick, oflire-brick or other suitable material, with a view of reducing to atallic frame partly closing the front of said casing. The dome C ispreferably of the shape illustrated tol support fire-brick or otherrefractory material a designed to lessen radiation of heat from thecasing top, and is provided with two longitudinal rows of collars b andan end opening 0,' the collars being for the connection of hot-air pipes(not shown), and the end opening o for the passage of the smoke uptake,or pipe presently described. The described arrangement of the collars.79 and opening o is obviously advantageous inasmuch as it admits of thedome being reversed when it is necessary for'the said smoke-uptake to bearranged adjacent to the front of the furnace, as sometimes occurs whenthe number of radiating flues is increased, as presently described. Thefront frame D is bolted to or otherwise suitably fixed with respect tothe casing A, and has lower and upper'flanges d and e and a duplexflange f arranged intermediate the flanges d and e; the said flangesbeing bolted or otherwise Xed upon 'the face of the frame.

As shown in Figs; l and 3, the frame D is equipped with two slidable,draft-con trolling doors g held between the flange d and the lowermember of the duplex flange two slidable doors L arranged between theupper flange e and the upper member of the duplex flange f, a hingedfuel door c' arranged above the doors 7L, and a suitable number ofhinged, clean-out doors j and 7c located above the fuel door. The doorsg are adapted to be slid apart to a greater or less extent, to admitair, and the doors la have their inner ends shaped to receive betweenthem a hydrocarbon burner E, which hydrocarbon burner may be of anyapproved construction and is arranged inthe reboX at a point immediatelyabove the grate, as shown in Fig. 3. It will also be observed in thisconnection that the inner ends of the doors 7L snugly fit about theportion of said burner which extends forward from the front of thefurnace.

As shown in Figs. 2 and 3 of the drawings,

extending, grooved fia-nge a, side walls J Y having inwardly-extendingledges p, Fig. 2, an upwardly and rearwardly inclined rear wall K, and abottom wall L. The said walls I, J, K and L are cast in one piece orotherwise ixed with respect to each other, air-tight so as to avoid anypossibility of gas, smoke or odor passing from the fire-box vinto theair space leading to air pipes The bottom wall L is provided with afront flange r to prevent the escape of excess hydrocarbon and is alsoprovided with a depression s which is designed to receive the excesshydrocarbon and is provided with a pipe for conveying the same to asuitable point of discharge. In this way it will be apparent thathydrocarbon dripping or overflowing from an oil-burner is conducted outof the furnace and is prevented from gathering in an unsightly anddangerous 'puddle in front of or being retained inside the furnace. Thiswill be appreciated as an important feature when it is remembered thatthe feeds to oil burners always leak when the burner is not inoperation, and that they often overflow while in operation, and that myimproved mode of disposing of the leakage and overflowed oil not onlyreduces the danger of fire and explosion to a minimum but obviates thedissemination of vapor andodor from the oil through a house.

The ash pit F and the fire-box G are separated by grate bars M arrangedon ledges p. The top wall I is lined with refractory material N as arealso the upper portions of the side walls J and the back wall K; theside ,and back sections of refractory material preferably resting on theledges p as shown.

Arrangedv above the fire-box and one above theother are a suitablenumber of spaced, radiating flues or conductors P for smoke, flames andvother products of combustion. Two of said flues are illustrated, and itwill be noticed that they are secured at their ends in the casing A, andthat their forward ends are controlled by the doors y' and 7c whiletheir rear ends are controlled by doors y" and c, Fig. 3, in order thatthey may be readily cleared of collected soot andl the like at intervalsin the use of the furnace. The lower flue Pis provided in its lower wallwith an opening a which is alined with the opening m of the fire-boxwall I and is surrounded by a depending, grooved flange o, andsaid flueis connected with the firebox G through the medium of a union R, the

edges of which are sealed by lire-putty or the like in the grooves ofthe flanges n and fu, as shown. The lower flue P is provided in itsupper wall adjacent to the front of the furnace with an opening fwsurrounded by a grooved flange a2, and the upper flue Pis provided inits lower wall above the opening w with an opening y having a dependinggrooved flange a. These openings fw and y are connected in the samemanner as the openings m and u-z'. e., through a union R, the edges ofwhich are sealed by fire putty in the grooves of the flanges m and y,Adjacent to the rear end of the furnace the top radiating flue P isprovided in its upper side with an opening c2 surrounded by an upwardlyextending, grooved ange a3 1n which is seated and sealed by fire puttythe lower end of the uptakeor smoke pipe T which may be connected with achimney or the like. At this point attention is directed to the factthat the unions R and the flues are interchangeable, and that in vorderto increase the capacity of the furnaces other radiating flues P may bearranged above the two illustrated, and, when necessary, the uptake orsmoke pipe T may be arranged adjacent to the front end of the furnacein# stead of near the rear end thereof. When other flues P are added,the casing A will obviously be increased in heightA and ,the dome C`raised to accommodate such additional flues, and shortened when thenumber of flues are decreased. By adding radiating flues P as stated,practically all of the heat of the product-sof combustion may beutilized to heat the fresh air conducted through the furnace, precedentto the pas sage of said products of combustion up the pipe T. y

The fresh air to be heated and supplied to apartments, is conducted intothe furnace through the pipe B, and is caused by walls or plates U totake a tortuous 'course around the fire box and Vbetween the radiatingilues P before it vpasses from the furnace through the collars b, withthe result that itis highly heated before it leaves the furnace.

It 'will be noticed that the fire-box G of my novel furnace is quite'large in proportion to the sizeof the furnace, and hence chunks androots of wood, paper, straw and analogous or soft coal may beconveniently burned in the fire-box; also, that access may be readilygained to the interior of the fire-box for repairs or other purposes.

In clearing the radiating flues of collected soot, the soot may bepushed through the medium of a suitable device to the openings in thebottoms of the flues, when the soot will drop vthrough said openings andeventually find its way from one to the other tothe lire# box and ashpit from whence it may be expeditiously and easily removed orburned.w

hereinbefore ascribed to my novel furnace, the said furnace isadvantageous because of its simplicity and cheapness, and the facilitywith which it may be built and lIept in repair.

The construction herein shown and described constitutes the bestembodiment of my invention known to me, but it is obvious that in thefuture practice of the invention such changes or modifications may bemade as fairly fall within the scope of my invention as claimed. Forinstance a water boX M7 may when desired be slidably mounted in the backwall of the casing A, Fig. 8.

Having described my invention, what I claim and desire to secure byLetters-Patent, is:

A furnace comprising a fire boX, a grate forming the bottom of the fireboX and adapted to support refuse therein, an ash pit disposed below thegrate and having abottom in which is a depression to receive excesshydrocarbon and also having a conduit leading from said depression to apoint outside the furnace, horizontally slidable doors mounted in thefront of the fire box and having meeting recesses in their inner ends,and a hydrocarbon burner extending between the doors and snuglyoccupying the recesses in the inner ends thereof and arranged a slightdistance above the grate.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

FRANK E. NELSON. Witnesses:

HARLEY E. HIGGINS, RUBEN S. SCHMIDT.

